Moisture-resistant and ppb-level trace chemical warfare agent optical gas sensor based on ZIF-67 3D photonic crystals with structural engineering

The rapid and trace detection of sulfur mustard (SM), a classical hazardous chemical warfare agents (CWAs) causing irreversible health damages and fatal, is an urgently serious issue for security safeguard but remains challenges especially in real -time changing atmospheric humidity. Herein, a zeolite imidazolate framework-67 (ZIF-67) three-dimensional (3D) photonic crystal optical sensor has been designed and proposed to detect trace SM simulants 2-chloroethyl ethyl sulfide (CEES). Compared to traditional semiconductors, the optical sensor can work at room temperature and shows significant moisture resistance. At real -time relative humidity (RH) of 35%, the sensor exhibits excellent selectivity among seven interfering gases due to the co-interactions of metal sites Co atoms of ZIF-67 via Co & sdot;& sdot;& sdot;Cl and Co & sdot;& sdot;& sdot;S with CEES (C4H9ClS), the ultralow detection limit (16.5 ppb), ultrafast response (0.5 s) for CEES can benefit from the ordered structure of ZIF-67 3D photonic crystal and its complete photonic bandgap. Most importantly, at higher RH 50%-95%, the sensor shows excellent moisture resistance and still keeps excellent selectivity, ultralow detection limit (19.1 ppb), ultrafast response (0.5 s), long-term stability and reusability for CEES even at RH 95%, warranting its utility as a moisture-resistant trace chemical warfare agent optical sensor.